It’s been tried before, this dressing up the men of Silicon Valley, and generally speaking it just doesn’t work.

But here comes Kristen Slowe with Saboteur, a line of clothing for the geek that comes with the taunting slogan: “You’re a man. Dress like one.”

Slowe doesn’t care that we are a valley of techies in T-shirts and jeans, Birkenstocks and flip-flops, shaggy shorts and ball caps. No matter that we are a place where guys make a fashion statement, a statement that goes roughly: We don’t care about fashion. Not a lick. Or that our fashion choices are often choices made from the pile of clothes we wore yesterday.

Slowe, you see, is inspired — primarily by her husband, a geek. Chris Slowe is the complete package: physics Ph.D. from Harvard, co-founder of startup Reddit, big fan of promotional T-shirts. He did manage a button-down shirt with his jeans when he and Kristen went on their first date about four years ago.

“Every date after that, it was like some T-shirt he picked up, some free T-shirt, and jeans,” says Kristen, 31. “I was horrified by it.”

In his defense, well, Chris Slowe, has no defense. But do you have any idea how many free T-shirts there are out there? “Free T-shirts are almost the currency of the startup world,” says Chris, 31, whose San Francisco company allows users to post links to their favorite Web content and critique the links of others.

And the Reddit co-founder wasn’t the only fashion failure, which Kristen would really like to make clear, because after all, she does have to live with the guy. As she made the rounds of Silicon Valley tech events she was taken by the utter fashion cluelessness of the area’s male inhabitants.

“There had to be something better when these guys have to go and pitch,” she says, as in a business plan, “or even go on a date.” A date? You’re joking, right? (OK, that’s mean.)

But the thing is, sloppy dress is part of the valley’s charm, part of its legendary meritocracy: It’s not what you wear, it’s what you invent. This is a place that inspired “The Nudist on the Late Shift,” a 1999 nonfiction book that included a passage about a programmer who worked, well, without wearing a stitch.

And now Kristen Slowe, who has an interest in fashion and a degree in product development, wants to cover the free spirits with sports jackets and shirts with fancy French cuffs.

“The point of this whole thing is to really just get guys to think about what they’re wearing. “It’s always had this ratty jeans and T-shirt reputation,” she says of the valley. “This is to put a better coat on it.”

Not to mention a nicer shirt.

For now, Slowe has come up with a modest line (if not modestly priced) of five jackets and six shirts. (No pants yet, should the nudist be reading.) Her San Francisco company sells them on the Web, with partner Justin Kan, 27, a friend and founder of live video site Justin.tv, who is helping out with the online particulars.

Slowe is not out of touch with the valley. Her signature piece is an $800 sports coat, the Invincible Jacket. “It’s essentially a Gore-Tex material,” she says. “It’s waterproof, breathable, stain-resistant. It won’t wrinkle.” If you spill on it, “it just beads right off. You just take a napkin to it.”

Meaning, of course, that you can code all night in it, wear it while napping under your desk, and clean the pizza you’ve slobbered on it by wiping it down with Wet Ones. Perfect.

Still, I fear Slowe is doomed. The valley’s slovenly look is entrenched. Some say it started decades ago when Hewlett-Packard employees would wear grubbies to work on Fridays, so they could help load products onto trucks. Others say it’s an extension of the college atmosphere that many companies foster. (Employees work on campuses, play foosball and create the future while sitting in bean bag chairs.)

Which is not to say Silicon Valley doesn’t have any sense of style. There’s Steve Jobs’ turtlenecks and Mark Zuckerberg’s hoodies.

“The hoodie and the turtleneck, those are things you could say make them noticeable,” Slowe says diplomatically. Jobs and Zuckerberg have reached a place in life (rich) where they don’t need to care about what they wear. “But for other guys,” Slowe says, “when you’re trying to get there, you have to put your best foot forward.”